Well alot of your flexibility is gain as a younger child and it's harder as you get older. Stretching is essential, and everday just aim a little higher on the bag, eventually you'll start working upwards..

Most power in the thai kick is from the swing motion in the hips. It is really hard to get good power with a lead leg kick because you have less range of motion in the leg and hips to generate power. A lead leg highkick isn't a very effective move IMHO but I'm sure someone will refute that. standard leg stretches will help with flexability and the standard excersises you practice at any Thai academy should help with power.

Yeah, I've never seen people effectively use a lead leg for any hurting power, only for points when I did Tae Kwon Do.

GSP KO'd Hughes with a lead leg kick. A cut kick from normal ready position will be more like a jab, but you can put one out with a bit of sting. If you proceed the kick with a full step forward, it would be more powerful than a standard kick from the rear leg.

Flexibility and form is key. Flexibility will help you carry power throughout a greater range of motion. Form/technique will ensure that you are generating a greater amount of power.

A great source book is this one: The Complete Mater's Kick by, Hee Il Cho. What's that? Don't complain that it's TKD. It's written by a man with over 30 years of experience while kicking. Adjusting the techniques for MT/MMA applications is not that hard.

If all else fails, find someone to train you. You will get a lot farther a lot faster with a trainer than you would trying to figure things out through trial-and-error.

__________________It doesn't matter if you agree or disagree... As long as I don't bore you and I spark a moment of thought, my goal is achieved.

GSP KO'd Hughes with a lead leg kick. A cut kick from normal ready position will be more like a jab, but you can put one out with a bit of sting. If you proceed the kick with a full step forward, it would be more powerful than a standard kick from the rear leg.

The step forward makes sense to get some forward momentum in the kick.